Maryland Code, Environment § 3-406

(a) A person who willfully violates any provision of this title or any rule, regulation, or order adopted or issued under this title is liable to a civil penalty not exceeding $10,000, to be collected in a civil action brought by a political subdivision in the circuit court for any county. Each day a violation continues is a separate violation under this section.

(b) The political subdivision may compromise and settle any claim for a civil penalty under this section.

(c) If, within 1 year after a civil penalty is compromised and settled under subsection (b) of this section, the person against whom the penalty is imposed satisfies the political subdivision that the violation has been eliminated or the order has been satisfied, the political subdivision may return to the person not more than 75 percent of the penalty paid.

(d) An action under this section is in addition to and not instead of an action for injunctive relief under § 3-405 of this subtitle.